How to align button centered below table?

I put form elements in a table so that column names and inputs are aligned to 2-columns.
And I put submit button and cancel button below the table.
The table width is not fixed.
I want to put the buttons center-aligned of the table width.

One simple way is to put the buttons in the table.
But I want to separate them from the table.
What's the most elegant way to do that?